Ipod Touch 4 Gen no Power after screen replacement

Alright, after changing the broken screen on my ipod touch 4 gen, i can't power on the device. This is not the first time i change

screen's on ipod's before. The power ribbon cable is ok and nothing has been damage internaly. The screen does work because

when i plug my ipod into the wall or computer, i get the charging battery screen. But even after leaving it 20 min on charge, ipod

still doesn't power on. Seems like the battery is not keeping it's charge anymore. But how would that even be possible after

changing a screen ? .... I also tried a hard reset when plugued in to my computer, iTunes detects the ipod in recovery mode, but the recovery

mode times out and gives out an arror, doesn't want to complete.

I really don't know what to try anymore, Even tried the old screen back and same problem. Do i need to repalce the battery ? ...

Please help